Young corals and fish in the Pacific Ocean can smell a bad neighborhood. When looking for a place to settle down, these animals use chemical cues to avoid reefs that are littered with seaweed and flock to healthy habitats instead, according to a new study.
Scientists have seen corals decline around the world over the past several decades, and the new findings help explain why some reefs aren't recovering or recruiting new corals, despite conservation efforts.
Fiji's "Coral Coast" might be an ideal lab to look at the difference between bad underwater neighborhoods and good ones. [Photos: Underwater Google Street View Reveals Stunning Corals]
"The reefs in Fiji have such a stark contrast between the healthy areas and the degraded areas," said Danielle Dixson, an assistant professor of biology at the Georgia Institute of Technology in Atlanta, who led the study.
Dixson and colleagues studied the waters off of three villages along the southern side of Fiji's main island, Viti Levu, which each managed a small marine protected area, or MPA, next to another area where fishing was allowed. Each MPA was a little less than a square kilometer in size (about 0.3 square miles) and had someone on patrol to enforce no-fishing laws 24 hours a day, Dixson told Live Science. Life thrives inside the MPAs, but the nonprotected areas often lack the large populations of herbivores, such as parrotfish, which would normally trim the seaweed from corals and keep them healthy, Dixson explained.